Add hook so sites can respond to route changes
Add hook so sites can respond to route changes

Khaledgarbaya/gatsby,ChristopherBiscardi/gatsby,gatsbyjs/gatsby,chiedo/gatsby,fson/gatsby,mingaldrichgan/gatsby,fk/gatsby,bzero/gatsby,MoOx/gatsby,ChristopherBiscardi/gatsby,danielfarrell/gatsby,mickeyreiss/gatsby,Syncano/gatsby,gesposito/gatsby,fk/gatsby,chiedo/gatsby,Khaledgarbaya/gatsby,0x80/gatsby,danielfarrell/gatsby,Khaledgarbaya/gatsby,ChristopherBiscardi/gatsby,alihalabyah/gatsby,okcoker/gatsby,domenicosolazzo/gatsby,gatsbyjs/gatsby,shaunstanislaus/gatsby,rothfels/gatsby,eriknyk/gatsby,gatsbyjs/gatsby,danielfarrell/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,chiedo/gatsby,mickeyreiss/gatsby,mingaldrichgan/gatsby,okcoker/gatsby,okcoker/gatsby,aliswodeck/gatsby,lanastasov/gatsby,gatsbyjs/gatsby,mickeyreiss/gatsby,fk/gatsby,gesposito/gatsby,fabrictech/gatsby,brianjking/gatsby,MariusCC/gatsby,fabrictech/gatsby,mingaldrichgan/gatsby,kidaa/gatsby,rothfels/gatsby,ChristopherBiscardi/gatsby,HaQadosch/gatsby,0x80/gatsby,0x80/gatsby,fabrictech/gatsby